Thermal damage in particulate-reinforced metal matrix composites

Thermal damage of SiC particulate-reinforced aluminum composites (MMCs) cau sed by laser thermal shock was investigated. The damage was induced by a co mbination of laser beam thermal shock and mechanical loads. The MMCs have t w kinds of particle distributions, one is uniform and another is heterogene ous. The damage initiation, crack propagation, as well as the failure evolu tion, were observed. A damage parameter was defined and it was tested. One found that the damage mechanism was very different for crack initiation and crack propagation and for MMCs with different spatial particle distributio ns. The mechanism of MMCs failure is discussed by the ideas of shear stress transfer between matrix and reinforcement. The discussion can explain the distinct mechanism of damage and failure in SiC particulate-reinforced alum inum composites.